It has been desirable to place on the surface of seats and backrests inflatable devices which will press on the body of the occupant in order to produce a massaging effect and thereby extend the time in which the seat can be used without discomfort to the occupant. In some of these devices, inflatable air cells have been provided on the seat surface and the inflation of the cells has produced a simple pulsating or intermittent surface pressure variation without producing a transitional pressure wave movement. While such movement has some effect in relieving discomfort, it has been long known that directional massage movement is more effective to relieve discomfort.
An example of a device which provides a transitional pressure wave movement for a massaging effect on a seat is disclosed in U.S. Pat. No. 3,613,671 to John H. Poor and Charles H. Logan. This patented device utilizes a rotating valve for sequentially inflating a plurality of inflatable air cells which are contained in a plurality of pockets in a fabric seat cover. A backing for the cells rests on the bottom and back seat surfaces to position the device on the seat. Thus, this patented device is entirely separate from the seat and is simply added threto when desired.